Method and system for power saving in wireless local area communication networks

• US 20080186890A1
• Filed: 02/06/2007
• Published: 08/07/2008
• Est. Priority Date: 02/06/2007
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Shao, Huai-Rong, Ngo, Chiu
• Granted Patent: US 7,710,939 B2
• Time in Patent Office: Days
• US Class Current: 370/311
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 52/0225 using monitoring of external events, e.g. the presence of a signal
• CPC Class Codes: H04W 52/0229 where the received signal is a wanted signal
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A power saving process for wireless communications is provided, wherein a receiving station examines the header of each incoming frame and stops decoding data symbols of the frame, upon determining that the incoming frame is not intended for that receiving station. In one implementation, the receiving station stops receiving and decoding data symbols of the frame by entering a power saving mode. This conserves power at the receiving station.

Claims

1. A power saving method for communication in a wireless network, comprising the steps of:

receiving a header of a transmitted data frame at a receiver;

checking the header to determine if the frame is intended for that receiver; and

stopping decoding of the frame, if the frame is not intended for that receiver.

2. The method of claim 1 further including the step of stopping receiving the frame and entering the receiver into a power saving state if the frame is not intended for that receiver.

3. The method of claim 2, wherein the remainder of the frame comprises the data payload of the frame.

4. The method of claim 2 wherein the step of entering a power saving state further includes the step of entering the power saving state before the end of the frame.

5. The method of claim 4 wherein the step of entering a power saving state further includes the step of entering the power saving state without receiving or decoding to the end of the frame.

6. The method of claim 2 wherein the step of checking the header further includes the step of checking a PHY header in the frame to determine if the receiver can support the capability required by the PHY header to receive the frame.

7. The method of claim 6 wherein:

the PHY header comprises a HT-SIG field;

the step of checking the PHY header further includes;

checking if an Advanced Coding (ADV) bit in the HT-SIG is set to “

1”

, such that if the receiver cannot support advanced coding, the receiver enters into standby during the frame period;

checking if a Space-Time Block Coding (STBC) bit in the HT-SIG is set to “

1”

, such that if the receiver cannot support the STBC function, the receiver enters into standby during the frame period;

checking if a Sounding Packet bit in the HT-SIG is set to “

1”

, such that the receiver cannot support transmit beamforming, the receiver enters into standby during the frame period;

checking if a 20/40 bandwidth (BW) bit in the HT-SIG is set to “

1”

to indicate the frame is transmitted in a 40 MHz channel, such that the receiver operates on a 20 MHz channel enters into standby during the frame period; and

checking the Modulation and Coding Scheme (MCS) indicated in the HT-SIG, such that if the receiver cannot support the MCS, then the receiver enters into standby during the frame period.

8. The method of claim 6 wherein the step of entering the receiver in a power saving state further includes the step of:

if the receiver cannot support the capability required by the PHY header, then concluding that the receiver is not the intended receiver of the frame and entering the receiver in a power saving state.

9. The method of claim 6 wherein:

the PHY header comprises a HT-SIG field; and

the step of checking the PHY header further includes the step of checking the HT-SIG field to determine if the receiver can support the capability required by the PHY header to receive the frame.

10. The method of claim 8 wherein:

the step of checking the PHY header further includes interpreting the HT-SIG field of the PLCP Protocol Data Unit (PPDU) format of the PHY header first before the entire frame payload arrives at a MAC layer of the receiver; and

the step of entering the receiver in a power saving state further includes entering the receiver in a power saving state if based on the interpretation, the frame is not intended for the receiver.

11. The system of claim 8 wherein:

the step of checking the header further includes the step of;

if the receiver can support the capability required by the PHY header, then checking a MAC header in the frame to determine if the receiver is identified therein; and

the step of entering the receiver in a power saving state further includes entering the receiver in a power saving state if the receiver is not identified in the MAC header.

12. The system of claim 8 wherein the step of checking the header further includes checking a MAC header control field, such that:

if a subfield Type<

>

“

10”

, then a power saving state is not triggered;

if a subfield To DS is “

1”

, then further CRC checking is terminated; and

if the entire MAC payload is not received by the MAC layer, then the receiver stops receiving and decoding the frame.

13. The system of claim 8 wherein the step of checking the header further includes checking a MAC header control field, such that:

if a subfield To DS is “

0”

, and the subfield Address 1 in the MAC header is not equal to the receiver address and is not a broadcast/multicast address, then further CRC checking is terminated;

if the entire MAC payload is not received by the MAC layer, then the receiver stops receiving and decoding the data frame.

14. The system of claim 8 wherein the receiver implements a type of IEEE 802.11n communication protocol.

15. The method of claim 2 wherein entering the receiver in a power saving state further includes the step of requesting a PLCP sublayer of a PHY layer in the receiver to stop receiving and decoding the frame.

16. The method of claim 2 wherein the receiver implements a type of IEEE 802.11 communication protocol.

17. The method of claim 2 further comprising the step of:

upon channel failure or carrier loss, entering the receiver in a power saving state until the end of the frame transmission duration.

18. The method of claim 2 wherein the frame comprises said header and data payload, such that the step of entering a power saving state further includes the step of entering the power saving state before decoding the payload of the frame.

19. The method of claim 18 wherein the step of entering a power saving state further includes the step of entering the power saving state before decoding to the end of the payload of the frame.

20. A wireless communication system, comprising:

a transmitter that is configured to transmit one or more data frames over a wireless channel; and

a receiver that is configured to receive one or more frames over the wireless channel, wherein the receiver comprises a power saving module that is configured to stop decoding of the frame, and enter the receiver into a power saving state if an incoming frame is not intended for the receiver.

21. The system of claim 20 wherein the power saving module comprises:

a receiving module that is configured to receive a header of a transmitted frame;

a checker that is configured to parse and check the header to determine if the frame is intended for that receiver; and

a controller that is configured to stop receiving and decoding the frame, enter the receiver in a power saving state if the frame is not intended for that receiver.

22. The system of claim 20 wherein the receiver is further configured to continue to receive and decode the remainder of the frame if the frame is intended for that receiver.

23. The system of claim 21 wherein the controller is further configured to enter a power saving state before the end of the frame.

24. The system of claim 23 wherein the controller is configured to enter a power saving state without receiving or decoding to the end of the frame.

25. The system of claim 21 wherein the checker is further configured to check a PHY header in the frame to determine if the receiver can support the capability required by the PHY header to receive the frame.

26. The system of claim 25 wherein the controller is further configured such that:

if the receiver can not support the capability required by PHY header, then the controller concludes that the receiver is not the intended receiver of the frame and enters the receiver in a power saving state.

27. The system of claim 25 wherein:

the PHY header comprises a HT-SIG field; and

the checker is further configured to check the HT-SIG field to determine if the receiver can support the capability required by the PHY header to receive the frame.

28. The system of claim 27 wherein:

the checker is further configured to interpret the HT-SIG field of the PPDU format of the PHY header first before the entire frame payload arrives at a MAC layer of the receiver; and

the controller is further configured to enter the receiver in a power saving state if based on the interpretation, the frame is not intended for the receiver.

29. The system of claim 26 wherein:

the checker is further configured such that, if the receiver can support the capability required by the PHY header, then the checker checks a MAC header in the frame to determine if the receiver is identified therein; and

the controller is further configured to enter the receiver in a power saving state if the receiver is not identified in the MAC header.

30. The system of claim 21 wherein the controller is further configured to enter the receiver in a power saving state by requesting a PLCP sublayer of a PHY layer in the receiver to stop receiving and decoding the frame.

31. The system of claim 20 wherein the receiver implements a type of IEEE 802.11 communication protocol.

32. The system of claim 21 wherein the controller is further configured to enter the receiver in a power saving state until the end of the frame transmission duration, upon detecting channel failure or carrier loss.

33. The system of claim 21 wherein the frame comprises said header and data payload, such that the controller is further configured to enter a power saving state before the payload of the frame is decoded.

36. The receiver of claim 21 wherein the controller is further configured to enter a power saving state before the end of the frame.

37. The receiver of claim 36 wherein the controller is configured to enter a power saving state without receiving or decoding to the end of the frame.

34. A wireless receiver, comprising:

a receiving module that is configured to receive a header of a transmitted frame over a wireless channel;

a checker that is configured to parse and check the header to determine if the frame is intended for that receiver; and

a controller that is configured to enter the receiver into a power saving state if the frame is not intended for that receiver.

35. The receiver of claim 34 wherein the frame comprises said header and data payload, such that the controller is further configured to enter a power saving state before the payload of the frame is decoded.

38. The receiver of claim 34 wherein the checker is further configured to check a PHY header in the frame to determine if the receiver can support the capability required by the PHY header to receive the frame.

39. The receiver of claim 38 wherein the controller is further configured such that:

if the receiver can not support the capability required by the PHY header, then the controller concludes that the receiver is not the intended receiver of the frame and enters the receiver in a power saving state.

40. The receiver of claim 38 wherein:

the PHY header comprises a HT-SIG field; and

the checker is further configured to check the HT-SIG field to determine if the receiver can support the capability required by the PHY header to receive the frame.

41. The receiver of claim 40 wherein:

the checker is further configured to interpret the HT-SIG field of the PPDU format of the PHY header first before the entire frame payload arrives at a MAC layer of the receiver; and

the controller is further configured to enter the receiver in a power saving state if based on the interpretation, the frame is not intended for the receiver.

42. The receiver of claim 39 wherein:

the checker is further configured such that, if the receiver can support the capability required by the PHY header, then the checker checks a MAC header in the frame to determine if the receiver is identified therein; and

the controller is further configured to enter the receiver in a power saving state if the receiver is not identified in the MAC header.

43. The receiver of claim 42 wherein the controller is further configured to enter the receiver in a power saving state by requesting a PLCP sublayer of a PHY layer in the receiver to stop receiving and decoding the frame.

44. The receiver of claim 43 wherein the receiver further includes a PHY_STANDBY.req() function, such that the controller is configured to enter the receiver into a power saving mode by invoking the PHY_STANDBY.req() function to request a PLCP sublayer of a PHY layer in the receiver to stop receiving and decoding the incoming frame.

45. The receiver of claim 44 wherein the receiver further includes a PMD_STANDBY.req() function, and the PHY PLCP sublayer is configured such that after receiving a PHY_STANDBY.req() request from the controller, the PHY PLCP sublayer sends a PMD_STANDBY.req() to a PMD sublayer of the receiver to stop receiving and decoding the frame.

46. The receiver of claim 45 wherein the controller is configured to utilize the PHY_STANDBY.req() and PMD_STANDBY.req() functions if the checker can finish parsing and checking the MAC header before the PHY layer completes decoding the incoming frame.

47. The receiver of claim 34 wherein the controller is further configured to enter the receiver in a power saving state until the end of the frame transmission duration, upon detecting channel failure or carrier loss.

48. The receiver of claim 34 wherein the receiver implements a type of IEEE 802.11 communication protocol.